Fat Block

[chubsta]

I have just installed late model 2.5L Carburettors on a low hours original fat block.
the carb. numbers are WMV18.
the jets from factory on the WMV18 range from 78 to 84.
why do Mercury have staggered jet sizes and will making them all the same do any damage.
should i down size the jets for the fat block and what size should i use.
i do not have a pyro and use NGK B8HS-10 spark plugs.

[TEXAS20225]

fat block 2.0 liter wmv 18 are from a 200 late model 2.5 what been done to it

[chubsta]

A fat block is a 2.4L.
no mods. done to either engine.

[wanagofass]

A fat block is a 2.4L.
no mods. done to either engine.
Im almost certain all the fat block motors use 2.0 sleeves and pistons, the early ones were based on a 2.4 block and the later ones on a 2.5 block, porting may be different between the two and that might make a jetting difference. Do you know what year the block is? I have a 99' fat block, it has wh28 but I can't remember the jet size.

[chubsta]

It is definetly a 2.4L.
A Fatblock is a 2.5L Block with 2.4L steel sleeves.
the head gaskets are also special one of a kind not used on any other V6 Mercury.